JP2666617B2 - Vibrating gyro - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope,
In particular, the present invention relates to a vibration gyro used for a navigation system mounted on an automobile, for example.

[0002]

2. Description of the Related Art FIG. 9 is an illustrative view showing one example of a conventional vibrating gyroscope. The vibrating gyroscope 1 includes a vibrator 2.
The vibrator 2 includes a vibrating body 3 having a triangular cross section, and piezoelectric elements 4a, 4b, and 4c are formed on three side surfaces of the vibrating body 3, respectively.

Further, one piezoelectric element 4c of the vibrator 2
Is electrically connected to the input terminal of the oscillation circuit 5, and the output terminal of the oscillation circuit 5 is electrically connected to the other two piezoelectric elements 4a and 4b. Therefore, the vibrator 2 is driven by self-excitation. Further, the two piezoelectric elements 4a and 4b are electrically connected to two input terminals of a detection circuit 6 including, for example, a differential amplifier. Therefore, the rotational angular velocity of the vibrating gyroscope 1 is detected by the output of the detection circuit 6.

[0004]

However, in a conventional vibrating gyroscope, when a large inertial force acts on the vibrator, a support member for supporting the vibrator may be plastically deformed. There is a problem of deterioration.

Therefore, the supporting member is less likely to be plastically deformed.
Vibration to cover the periphery of the support member.
It is conceivable to provide a dynamic absorber. However,
When a vibration absorbing material is provided so as to cover the periphery of the holding member,
Vibration absorption due to changes in ambient temperature, humidity, and aging
The support state of the vibrator changes due to changes in the hardness of the collected material
Vibration gyro characteristics may change or drift may occur.
And the reliability is poor. Another object of the present invention, the support member for supporting the vibrator rather difficulty plastically deformed, reliability is not good, is to provide a vibrating gyroscope.

[0006]

According to the present invention, there is provided a vibrator,
A vibrating gyroscope including a support member for supporting the vibrator, a fixed plate to which the support member is fixed, and a protection member formed on the fixed plate and provided at a distance from the support member near the support member. .

[0007]

The protective member formed on the fixing plate and provided in the vicinity of the supporting member prevents the supporting member fixed to the fixing plate from being displaced more than necessary, thereby making it difficult for the supporting member to be plastically deformed. In addition, the protection member and the support member
Since it is provided at intervals, changes in ambient temperature and humidity
Of the vibrator almost changed due to
Gyro characteristics change and drift occurs
There is almost no risk of dropping, and the reliability is good.

[0008]

Effects of the Invention According to the present invention, the support member for supporting the vibrator rather difficulty plastically deformed, have good reliability, vibration gyro is obtained. Therefore, in the vibrating gyroscope according to the present invention, deterioration of characteristics due to plastic deformation of the support member is less likely to occur.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0010]

FIG. 1A is a schematic front view showing an embodiment of the present invention, and FIG. 1B is a schematic side view thereof. FIG. 2 is an exploded perspective view of the vibrating gyroscope shown in FIG. FIG.
FIG. 2 is a circuit diagram of the vibration gyro shown in FIG. FIG. 4 shows FIG.
FIG. 3 is an exploded perspective view showing a main part of the vibrating gyroscope shown in FIG.

The vibrating gyroscope 10 includes a vibrator 12. The vibrator 12 includes a vibrator 14 having, for example, a triangular cross section, as shown in FIG. The vibrating body 14 is made of, for example, a constant elastic metal material such as nickel, iron, chromium, titanium, or an alloy thereof such as elinvar or an iron-nickel alloy. Note that the vibrating body 14 may be formed of a material other than a metal that generally generates mechanical vibration, such as quartz, glass, quartz, or ceramic.

As shown in FIG. 3, the vibrating body 14
Piezoelectric elements 16a, 16b and 16c are fixed to the centers of the three side surfaces, respectively. These piezoelectric elements 16
a to 16c each include a piezoelectric layer 18 made of, for example, a ceramic, and an electrode 20 is provided on both main surfaces of the piezoelectric layer 18.
a and 20b are formed respectively. The electrodes 20a on one main surface of each of the piezoelectric elements 16a to 16c are
It is bonded to the side surface of the vibrating body 14 with, for example, a conductive adhesive. In this embodiment, the two piezoelectric elements 16a and 16b are used for driving to vibrate or drive the vibrating body 14 and for detecting the displacement of the vibrating body 14, and another piezoelectric element 16a and 16b are used. The element 16c is used for feedback for returning the drive signal to the two piezoelectric elements 16a and 16b.

The vibrator 12 is supported by two support members 22a and 22b, as shown in FIG.
The support members 22a and 22b are each formed in a U-shape with a wire such as a metal. The central portions of the support members 22a and 22b are
It is fixed to one ridge line portion of the vibrating body 14 sandwiched between a and 16b. In this case, the support members 22a and 22b
Is fixed in the vicinity of the node point of the vibrating body 14 in order to make the vibration of the vibrating body 14 hardly adversely affected. In this embodiment, assuming that the length of the vibrating body 14 is L, these support members 22a and 22b are fixed at positions 0.224L from both ends of the vibrating body 14.

These support members 22a and 22b are
For example, it is fixed to the vibrating body 14 by bonding with an adhesive, soldering, or welding, but when fixing by soldering or welding,
Considering both the strength of the support member and the solderability or weldability of the support member to the vibrating body, for example, nickel, platinum, gold, silver, or the like, around a strong metal wire such as molybdenum or titanium. A wire coated with a material with good solderability and weldability such as copper, stainless steel, iron, etc.
Preferably, a support member is formed.

As shown in FIGS. 4 and 5, both ends of these support members 22a and 22b are made of, for example, iron,
They are fixed to, for example, substantially rectangular fixing plates 24a and 24b made of a metal material such as nickel and stainless steel. That is, two holes 26 are formed in each of the fixing plates 24a and 24b. Then, both end portions of one support member 22a are connected to two of the one fixing plate 24a.
The two holes 26 are inserted and soldered. Similarly, both ends of the other support member 22b are connected to the other fixing plate 24b.
And soldered.

At one end of each of the fixed plates 24a and 24b, for example, a substantially U-shaped plate-like piece member 28 is formed so as not to contact the vibrator 12. Further, for example, a plate-shaped protection member 30 is formed at each of both ends in the width direction of the piece members 28. These protective members 30 prevent the support members 22a and 22b from being displaced more than necessary in the width direction of the vibrator 12, and
is intended to protect a and 22b, supported in the vicinity of the supporting members 22a and 22b member 22a and 22
b and the supporting members 22a and 22b
It is arranged inside. The one-piece member 28 and the protection member 30 are formed integrally with the fixing plates 24a and 24b.

The fixing plates 24a and 24b are shown in FIG.
As shown in FIG. 4 and FIG.
The support plates 2a and 32b are fixed to one main surface of, for example, a strip-shaped support plate 34 made of a magnetic and conductive material such as iron, nickel, and stainless steel.

As shown in FIGS. 4 and 6, the support plate 34 is formed with leg members 36a and 36b extending downward from one end and the other end in the longitudinal direction. One protruding portion 38 is formed in the center of the lower end of the leg member 36a on one end side in the longitudinal direction of the support plate 34. Further, two projections 40 are provided on both sides of the other end of the support plate 34 in the longitudinal direction.
a and 40b are formed. These projections 38, 4
0a and 40b correspond to the circuit board 4 to be described later.
6 to be used for fixing. In addition, two holding pieces 42 are formed at one end in the width direction of the support plate 34 at a predetermined interval, and two holding pieces 42 are formed at the other end of the width direction at a predetermined interval. Is done. These holding pieces 42 are used for holding the work cover 56 described later on the support plate 34.

At the center of one main surface of the support plate 34, a positive temperature coefficient thermistor 44 is mounted as shown in FIG. The positive temperature coefficient thermistor 44 is for keeping the temperature of the vibrator 12 stable. That is, a constant voltage is applied to the PTC thermistor 44. If the temperature of the vibrator 12, that is, the temperature around the positive temperature coefficient thermistor 44 increases, the resistance of the positive temperature coefficient thermistor 44 increases, the amount of heat generated therefrom decreases, and the temperature around the temperature decreases. When the temperature decreases, the resistance of the positive temperature coefficient thermistor 44 decreases, the amount of heat generated therefrom increases, and the temperature around it increases. Therefore, the temperature of the vibrator 12 is stably maintained by the positive temperature coefficient thermistor 44.

The support plate 34 is attached to one main surface of the circuit board 46 as shown in FIGS. In this case, the protrusion 38 of the foot member 36a on one end side of the support plate 34
Is inserted into the circuit board 46 and soldered to a ground pattern (not shown) on the other main surface of the circuit board 46. Therefore, the support plate 34 includes two foot members 36a and 36
It is fixed to the circuit board 46 while being floated from one main surface of the circuit board 46 at b.

Further, between the support plate 34 and the circuit board 46, a sheet-like cushion material 48 is adhered to the center of one main surface of the circuit board 46 with an adhesive. The cushion material 48 is formed of a material which is foamed so-called independent foamed rubber such as rubber such as butyl rubber or synthetic resin such as urethane so that each bubble is not connected.

Further, on one main surface of the circuit board 46, for example, a U-shaped relay board 50 is attached outside the other end in the longitudinal direction of the support plate 34. The relay board 50 has three terminals 52a, 5a extending parallel to the main surface and extending outside thereof.
2b and 52c are formed parallel to each other. These terminals 52 a to 52 c are penetrated by the circuit board 46 and are soldered to three conductor patterns (not shown) on the other main surface of the circuit board 46. Therefore, the relay board 50 is mounted on the circuit board 4 such that one main surface thereof faces the end face on the other end side in the longitudinal direction of the support plate 34.
6 is fixed.

The relay board 50 includes a support plate 34.
Are inserted, and the projections 40a and 40b are soldered to a conductor pattern (not shown) on the other main surface of the relay board 50. Therefore, via the relay board 50, the support plate 34
It is more firmly fixed to the circuit board 46.

Further, on the other main surface of the relay board 50, 3
Three conductor patterns 54a, 54b and 54c are formed, and three terminals 52a to 52c are electrically connected to these conductor patterns 54a to 54c, respectively. The electrodes 20b on the other main surfaces of the three piezoelectric elements 16a to 16c of the vibrator 12 are electrically connected to these conductor patterns 54a to 54c by lead wires (not shown), respectively.

The support plate 34 is made of, for example, iron, nickel,
A work cover 56 made of a magnetic and conductive material such as stainless steel is attached. Work cover 5
4 includes a strip-shaped main surface member 58, and side surface members 60 extending downward from both ends in the width direction are formed on the main surface member 58, respectively, as shown in FIGS. The center of the lower end of each of these side members 60 is formed as a protruding portion 62 that protrudes outward. The main surface member 5
8, protection members 64 having, for example, an L-shaped cross section are formed at both ends in the longitudinal direction. In the work cover 56, the side members 60 are fitted inside the holding pieces 42 of the support plate 34, and the protruding portions 62 of the side members 60 are fitted between the holding pieces 42. In this case, the two protection members 64 are arranged near the outer sides of both ends in the longitudinal direction of the vibrator 12 with an interval from the vibrator 12 . These protection members 64 prevent the vibrator 12 from being unnecessarily displaced in the longitudinal direction, that is, the support member 22.
This is to protect the support members 22a and 22b by preventing the a and 22b from being displaced more than necessary in the longitudinal direction of the vibrator 12.

On the other hand, on the other main surface of the circuit board 46, FIG.
As shown in the figure, an oscillation circuit 66 and a detection circuit 68 are mounted.

The oscillation circuit 66 is for driving or vibrating the vibrator 12, and includes a crystal for stabilizing the oscillation frequency and a phase correction circuit for adjusting the oscillation frequency. The input terminal of the oscillation circuit 66 is connected to a conductor pattern (not shown) and the relay board 5 as shown in FIG.
The piezoelectric element 1 of the vibrator 12 is
6c is electrically connected to the electrode 20b, the output terminal of the oscillation circuit 66 is divided by a variable resistor 72a, and the piezoelectric element 16a is separated through another conductor pattern (not shown), terminals 52a and 52b, and the like. And 16b, respectively.

The detection circuit 68 is for detecting the displacement of the vibrator 12, and is composed of, for example, a differential amplifier. Two input terminals of the detection circuit 68 are connected to the electrodes 20b of the piezoelectric elements 16a and 16b via conductor patterns (not shown), terminals 52a and 52b, and the like.

Further, three variable resistors 72a, 72b and 72c are mounted on the other main surface of the circuit board 46, as shown in FIG. One variable resistor 72a balances the output of the oscillation circuit with good balance between the piezoelectric elements 16a and 16a.
b. Also, another variable resistor 72b
Is for adjusting the level of an input signal input to the detection circuit 68, and is connected between two input terminals of the detection circuit 68 as shown in FIG. Further, the remaining variable resistor 72c is for adjusting the level of the output signal of the detection circuit 68, and is connected between the output terminal of the detection circuit 68 and the ground.

Further, on the other main surface of the circuit board 46, as shown in FIGS.
A shield cover 74 made of a magnetic, conductive, and elastic material such as iron, nickel, or stainless steel is attached so as to cover the resistor 8 and the variable resistors 72a, 72b, and 72c. Shield cover 74
Includes a rectangular plate-shaped main surface member 76 having substantially the same width as the circuit board 46, as shown in FIGS. The main surface member 76 has its central portion in the width direction bent outward. Side members 78a and 78b are formed at both ends in the width direction of the main surface member 76, respectively. Further, projections 80 are formed at both ends of the side members 78a and 78b, respectively. Then, the projections 80 are inserted into the circuit board 46 and soldered to a ground pattern (not shown) on one main surface of the circuit board 46. The shield cover 74 includes a side member 78.
a, three holes 84a, 84b and 84c corresponding to the adjusting screws of the three variable resistors 72a to 72c are formed.

On one main surface of the circuit board 46, a plurality of power terminals for supplying power to the positive temperature coefficient thermistor 44, the oscillation circuit 66 and the detection circuit 68, and output terminals for extracting output signals of the detection circuit 68 are provided. Of the positive characteristic thermistor 4 via a conductor pattern (not shown) of the circuit board 46 or the like.
4, connected to the oscillation circuit 66 and the detection circuit 68.

The vibrator 12, the circuit board 46, the work cover 56, and the like are housed in a box-shaped case 92 together with the two cushion members 88 and 90, as shown in FIGS. .

The cushion member 88 is formed, for example, in a rectangular plate shape, and is arranged on the upper surface of the work cover 56. Further, the cushion material 90 is provided at the center thereof with the work cover 56.
Are formed on the side surface of the work cover 56. These cushions 88 and 90
Is formed of a material obtained by foaming a synthetic resin such as rubber such as butyl rubber or urethane such that the respective bubbles are not connected, similarly to the cushion material 48 described above. These cushion members 48, 88 and 90 are connected to the vibrator 1.
The purpose of this is to enhance the heat insulating effect between the surroundings of the 2 and the outside, to absorb unnecessary sound waves from the outside to the vibrator 12, and to prevent leakage of vibration from the vibrator 12 to the outside.

An opening 94 is formed in the case 92 so as to correspond to the terminal 86. In particular, as shown in FIG.
The terminal 86 is exposed from the opening 94. Further, as shown in FIG.
a and 72c, corresponding to the adjusting screws, two holes 96a and 96 for externally adjusting the adjusting screws.
b is formed.

As shown in FIGS. 1 and 2, a rectangular plate-shaped back cover 98 made of a conductor such as aluminum is attached to the case 92 with screws 100. In this case, since the widthwise center of the main surface member 76 of the shield cover 74 having elasticity is bent outward, the back cover 98 is attached to the shield cover 7.
4 is pressed against the shield cover 74 and electrically connected to the shield cover 74.

In the vibrating gyroscope 10, since the protection member 30 is provided near the inside of the supporting members 22a and 22b for supporting the vibrator 12, the supporting member 22
Since a and 22b are not unnecessarily displaced in the width direction of the vibrator 12, plastic deformation hardly occurs. Therefore, deterioration of characteristics due to plastic deformation of the support members 22a and 22b is prevented. Further, since the support members 22a and 22b are not displaced in the longitudinal direction of the vibrator 12 more than necessary by the protection member 64 of the work cover 56 provided near the outside of both ends in the longitudinal direction of the vibrator 12, the support member 22a
And 22b are prevented from deteriorating in characteristics due to plastic deformation. In order to prevent the deterioration of the characteristics due to the plastic deformation of the support members 22a and 22b, the protection member is attached to the vibrator 1
2 or the vicinity of the support members 22a and 22b, and the shape of the protection member is not limited to a plate shape but may be a block shape. Also, with this vibrating gyro 10
In other words, the protection members 30, 64 are supported by the support members 22a, 22b and
And at a distance from the vibrator 12
Supporting the vibrator 12 by changing the degree, humidity, and aging
The state hardly changes, and the characteristics change and drift
And there is almost no possibility of occurrence, and the reliability is good.

Further, in the vibrating gyroscope 10, the cushion member 4 made of a independently foamed material is provided around the vibrator 12.
8, 88 and 90 are provided, so that the vibrator 12
The heat insulating effect between the surroundings and the outside is good, unnecessary sound waves from the outside to the vibrator 12 can be absorbed, and leakage of the vibration from the vibrator 12 to the outside can be prevented. Therefore, it is possible to prevent deterioration in characteristics due to external temperature changes and external sound waves, and to prevent leakage of vibration from the vibrator 12 to external devices.

Further, in the vibrating gyroscope 10, since the positive temperature coefficient thermistor 44 is provided near the vibrator 12, the temperature of the vibrator 12 can be kept stable. Therefore, deterioration of characteristics due to a temperature change can be suppressed. In order to keep the temperature of the vibrator 12 stable, the vibrator 1
2 is provided in the vicinity of the positive characteristic thermistor 44 in place of the positive characteristic thermistor 44, for example, a negative characteristic thermistor, a nichrome wire, a ceramic heater, and the like. A detector may be provided to turn on and off the heater based on the detection by the temperature detector.

In the vibrating gyroscope 10, since the support plate 34 and the work cover 56 are provided around the vibrator 12 as a shielding material made of a magnetic material, the vibrator 12 is magnetically shielded from the outside. As a result, deterioration of characteristics due to external magnetism can be prevented.

Further, in the vibrating gyroscope 10, the circuit board 46 is connected via the terminals 52a to 52c of the relay board 50.
Is electrically connected to the oscillation circuit 66 and the detection circuit 68 on the other main surface side of the circuit board 46, so that the vibrator 12 provided on the one main surface side of the circuit board 46 There is no need to run lead wires on the side.

Further, in the vibrating gyroscope 10, since the shield cover 74 made of a magnetic material is provided so as to cover the oscillation circuit 66 and the like, high frequency noise generated from the oscillation circuit 66 can be prevented. it can.

Further, in the vibrating gyroscope 10, since the back cover 98 is electrically connected to the shield cover 74 which is set to the ground potential, it is easy to connect to the external ground potential. Further, the back cover 98 is simply and electrically connected to the shield cover 74 simply by pressing the back cover 98 against the elastic force of the shield cover 74. Thus, the shield cover 74 and the back cover 98
In order to electrically connect the shield cover 74 and the back cover 98 with an elastic material, at least one of the shield cover 74 and the back cover 98 is formed, and the back cover 98 is crimped to the shield cover 74 against the elastic force. What should I do?

In the above-described embodiment, the vibrator 14 of the vibrator 12 has a triangular cross section.
May be formed in a rectangular cross section. In this case, the piezoelectric elements may be formed on four side surfaces of the vibrating body.

[Brief description of the drawings]

FIG. 1A is a schematic front view showing an embodiment of the present invention, and FIG. 1B is a schematic side view thereof.

FIG. 2 is an exploded perspective view of the vibrating gyroscope shown in FIG.

FIG. 3 is a circuit diagram of the vibrating gyroscope shown in FIG.

FIG. 4 is an exploded perspective view showing a main part of the vibration shilo shown in FIG.

5A is a schematic front view showing a structure for supporting the vibrator of the vibrating gyroscope shown in FIG. 1, and FIG. 5B is a schematic side view thereof.

6A is a front view of a support plate used in the vibrating gyroscope shown in FIG. 1, FIG. 6B is a plan view thereof,
(C) is a side view thereof.

7A is a front view of a work cover used in the vibrating gyroscope shown in FIG. 1, FIG. 7B is a plan view thereof, and FIG. 7C is a side view thereof.

8A is a front view of a shield cover used in the vibrating gyroscope shown in FIG. 1, FIG. 8B is a plan view thereof, and FIG. 8C is a side view thereof.

FIG. 9 is an illustrative view showing one example of a conventional vibrating gyroscope;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration gyroscope 12 Vibrator 22a, 22b Support member 30, 64 Protection member

Claims (1)

(57) [Claims] 1. A vibrator, the supporting member for supporting the vibrator, a fixing plate to the support member is fixed, and is formed on the fixing plate, the support in the vicinity of the support member
A vibrating gyroscope including a protection member provided at an interval from a member.